Formal Verification in Analysis and Design of Production Systems

In this paper the capability of a new approach to the detailed evaluation of production systems behaviour is investigated. Formal verification techniques, whose natural application domain is the design phase of IT systems, are used to prove structural properties of production systems. These techniques employ formal models (usually based on the classic theory of finite state automata) for systems description, and they are used to mathematically verify if systems satisfy desired correctness properties. More in detail, this paper proposes a formal, state-based model for Flexible Manufacturing Systems (FMS), which is used to check the validity of some properties during the detailed design of FMSs, where the designer is interested to verify the value and correctness of his/her decisions. The proposed verification technique, known in computer science literature as model checking, checks if a system satisfies a certain property or not by trying to find proper counterexamples (if the property does not hold for the system, a counterexample is produced). Some interesting properties investigated in this paper relate to production rate and flowtime bounds, machine and tool utilization. A case study considering a real FMS is used to show the applicability of the approach.